at fist u'll think im being an idiot but it honestly works a charm aye as im doing it on my four foot tank. just get one of those cheap blueplanet tankmaid internal filters, the largest one apparently flows 1000l/hr. i took all 3 compartments apart and broke off all the bottom grid bits making it one whole chamber/compartment and then just stuff it full of filter wool. only needs changing like every fortnight and its easy as to change the wool, there cheap to buy as well. i really noticed the difference aye, no more tiny little particles anywhere.